IDVE

Set to 3 different clues across 3 published puzzles, most often "If only ___ known ..." — The New York Times, Sunday, 4 October 2009.

4 letters

Every clue on record, most used first

"If only ___ known ..."once
The New York Times — Sunday, 4 October 2009
Double contractiononce
The New York Times — Wednesday, 9 March 2005
"If I Knew You Were Comin' ___ Baked a Cake"once
The New York Times — Wednesday, 12 February 1997